Using a giant needle as an example in the video far below, you will learn the various parts of a needle, as well as the importance of having a smoothly finished eye.
One of our favorite needles to recommend is a Microtex Schmetz. They're sharp and they pierce exactly at the point of fabric entry, allowing you to be as accurate as possible with your piecing. While the Universal needle is great for everyday sewing, the stitch is less than perfect on a high-thread-count, fine cotton. It is neither sharp nor ball point and has a tendency to pierce the fabric on either side of the thread weave.
For most piecing with quilter's cottons an 80/12 will be a sufficient size, but if you work with Liberty Lawns, Batiks, or any other finely woven fabric, then a 70/10 will be best - just be sure to use a finer thread as well, such as Aurifil 50wt or Presencia 60wt cotton. One of the things that April mentions at our Featherweight Maintenance Workshops is that you don't want the thread to be stronger than the fabric you are sewing with, namely heirloom quilts or clothing. While that might seem counter-intuitive, it is much easier to repair a popped seam than it is to repair a frayed seam, especially cotton fabric that has rubbed and pulled against a much stronger polyester thread.
For example, think about those old antique quilts you have inherited. A popped seam from thread that has broken from normal wear, shifting and use on a bed is easier to quickly mend by hand than it is to try and fix a piece that has frayed and pulled away from the seam altogether.
So, save that polyester thread for craft projects or for mending your husband's heavy work clothes, and invest in some Microtex needles (along with a quality cotton thread) for those beautiful quilts you make and pass on to future generations.
Regarding the smoothly finished eyes -- Singer of old made a very good quality needle with their standards superior compared to their standards today, in my opinion. In fact, if you want to, you can still make use of those vintage Singer packets in your old Singer Featherweight, so long as they're made in USA, Germany or Great Britain. However, in our experience of needles, the new Singer packets that are made in Malaysia, Singapore, Brazil, etc. are prone to rougher-finished eyes which cause frayed or broken thread.
Another very important tip: If you are going to make use of those old, unused Singer packets, you must know that they will work fine in your Singer Featherweight but not in your new, modern-day, household sewing machine. The reason is because they do not have the 'H' indication on the packet, or "scarf" part of the needle, as illustrated in the video. New, modern-day, household sewing machines require needles to have that 'H' or scarf indication.
That said, in today's quilting world, the Microtex Schmetz is much more preferred for better accuracy. Therefore, it might be better to save those nostalgic vintage Singer packets for your sewing room display and invest in a good Schmetz Microtex needle.